[Suharshit]

Stacked on #21. The base is feat/ai-sessions-storage, so this diff shows step 2 only. Merge #21 first, then change this PR's base to main.

Why

The AI sidebar lost its chat and any in-flight run on reload. This is step 2 of the AI sessions plan: the chat now reads and writes the sessions stored in #21. Generation is still one prompt → one design run; the clarify → plan → generate flow is step 3.

What

• New turns route: POST /api/projects/[projectId]/ai-sessions/[sessionId]/turns with { type: "message", text }.
  • It checks access, then rejects with 409 if a reply is still pending or the chat would pass 60 messages.
  • It triggers design-agent and stores the prompt plus a PENDING reply carrying the run id. It also records the TaskRun row, moves the expiry forward and titles the chat from its first message.
  • If the trigger fails, it still stores the prompt with an error reply and returns 502.
• Saving replies: GET .../ai-sessions/[sessionId] saves any finished runs before returning.
  • It reads each pending run with runs.retrieve. A success is saved as a RESULT with node and edge counts; a failure, cancellation or missing run becomes an ERROR.
  • A reply is therefore saved even if the tab closed mid-run, and the Trigger task still needs no database access.
  • When two reads settle the same reply at once, only one write happens and both return the saved reply.
• Removed: POST /api/ai/design. The token route is unchanged.
• Hook: useAiSession replaces useDesignAgent.
  • It reopens the chat last opened in this browser, or the most recent one.
  • A new chat is only stored when its first message is sent.
  • While a reply is pending it follows the run live through Trigger Realtime, and also re-reads the session every 4s in case the live connection drops.
• Sidebar: a session bar with the current title, a saved-chats list (last activity, expiry, delete) and New chat, plus a loading state, a retryable load error, and scrolling to the latest message.
• Refactors: the limit constants moved to lib/ai/session-limits.ts so the client can import them without Prisma. formatRelativeTime moved to lib/relative-time.ts.

Verification

• pnpm typecheck and pnpm lint pass.
• Database script:
  • a run that doesn't exist is saved as a failed reply
  • concurrent reads settle a reply once
  • a full chat or an unknown session is rejected
  • a pending reply blocks a new message (409)
  • a trigger failure returns 502 with the prompt stored before the error reply and no TaskRun row
• Full run through a local trigger dev worker, on a throwaway project and Liveblocks room that were removed afterwards:
  • 202 with a PENDING reply and a TaskRun row
  • 409 for a second message while pending
  • the reply saved as "Added 3 components and 2 connections to the canvas."
  • re-reading the session changed nothing
• Signed-out requests to the new routes are stopped by Clerk.
• Not checked in a browser: the sidebar UI, resuming after a reload, switching and deleting chats, and the live progress line.

🤖 Generated with Claude Code

[vercel]

The latest updates on your projects. Learn more about Vercel for GitHub.

Project	Deployment	Actions	Updated
draftly	Ready	Preview	Sep 15, 2026 6:42pm UTC

[coderabbitai]

Important

• 🔍 Trigger review

This repository does not receive automatic reviews because it has fewer than 10 stars.

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Advanced

Run ID: b5368e3a-b424-450c-9816-6000f66afd83

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands.}